000
FXUS63 KGID 181156
AFDGID
Area Forecast Discussion
National Weather Service Hastings NE
656 AM CDT Sun Mar 18 2018
.UPDATE...
Issued at 647 AM CDT Sun Mar 18 2018
Just sent an update to lower high temperatures by a few degrees
with cloud cover likely being lower and more widespread than
expected. Current forecast is for upper 40s to low 50s, but if
the HRRR/RAP is correct, we could even end up being colder still.
&&
.SHORT TERM...(Today through Monday Night)
Issued at 348 AM CDT Sun Mar 18 2018
In the near-term, fog remains the main question. So far, models
have been overdoing the fog potential. We`ve seen no fog
yet...probably because winds have stayed in the 5-10 MPH range
overnight. That said, I will go ahead and keep some patchy fog in
the grids as I think there is still a chance for some lower
visibilities near dawn.
Meanwhile, an upper leveltrough will approach the area, bringing a
good chance for showers to the area this evening. There may be just
enough instability across southern parts of the area for a few
rumbles of thunder as well. SPC has the "marginal" risk clipping our
southernmost KS counties, with the concern being large hail. RAP
and NAM both show over 500J/kg of MUCAPE over portions of Kansas,
which could be sufficient for some hail. That said, it appears
unlikely any storms will be severe in our area.
Late tonight through Monday morning, we may see rain transition to a
rain/snow mix or even all snow at some locations across south
central Nebraska. Mesoscale models (NAM, ARW, NMM) are the most
aggressive with the snowfall, but all of these models overdid the
snow in the last system as well. That said, the 0Z ECMWF is now
showing some support for snow as well. Low temperatures will only
be in the 30s, so snow will be very wet and most accumulation will
be on grassy surfaces.
Heading into Monday, I expect periods of rain and snow to continue
through the day as low pressure system passes to our southeast and
another northern-stream wave moves into the area. Significant
snow accumulations are unlikely during the daytime hours thanks to
the springtime sun angle and high temperatures in the low 40s.
North winds are also expected to gust to around 30 MPH through the
day on Monday.
Monday night, the secondary wave will continue to push across the
area, continuing the rain/snow mix through the overnight hours.
Total snow accumulations for Sunday night through Monday night
are forecast to range from 0 to 2" across parts of south central
Nebraska. That said, uncertainty is higher than normal with this
system, as just a couple degrees difference will significantly
change the amount of snow.
.LONG TERM...(Tuesday through Saturday) Issued at 348 AM CDT Sun
Mar 18 2018
We will start seeing a push of drier air Tuesday morning, which
should bring an end to precipitation across the area. Northerly flow
will continue on Tuesday, which will limit temperatures to the 40s
to perhaps low 50s.
On Thursday, upper level ridging moves overhead and we will see
southerly flow at the surface. This should allow for a much nicer
day with highs in the 60s to near 70 degrees.
The first of a series of disturbances is forecast to pass through
the area Thursday night into Friday morning. While it could bring
some rain to portions of the area, it appears that the bulk of
the activity will be east of the area.
Friday should turn out to be a relatively nice day with high
temperatures in the 60s and 70s. With gusty south winds, we will
also need to keep an eye on the fire danger. Of course this could
still be impacted by lingering cloud cover.
A second storm system is expected to move through the area Saturday
into Sunday, but details on this system vary quite a bit from
model to model.
&&
.AVIATION...(For the 12Z KGRI/KEAR TAFS through 12Z Monday)
Issued at 621 AM CDT Sun Mar 18 2018
We haven`t had much for fog tonight, but we do have an area of
LIFR ceilings expanding over central Nebraska currently. I think
we still could get a brief period of fog this morning, so I went
ahead and included 1SM in a tempo group for the next few hours.
This is another low-confidence forecast, but it now appears that
we will have low clouds around through the morning
hours, only lifting to MVFR for a time this afternoon as mixing
increases.
Periods of rain and lower ceilings move back into the area in the
evening. I haven`t included it in the current TAF, but there is
also a chance for a mix of rain and snow late overnight tonight
into Monday morning.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
UPDATE...Mangels
SHORT TERM...Mangels
LONG TERM...Mangels
AVIATION...Mangels